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  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  To 
  prepare 
  the 
  same 
  raw 
  materials 
  for 
  shaft 
  kilns 
  of 
  any 
  type 
  

   requires 
  three 
  handlings, 
  namely 
  grinding 
  the 
  rock, 
  making 
  the 
  

   ground 
  rock 
  into 
  bricks 
  or 
  balls, 
  drying 
  the 
  bricks. 
  

  

  In 
  Pennsylvania 
  a 
  portion 
  of 
  natural 
  rock 
  cement 
  is 
  regularly 
  

   added 
  in 
  the 
  rock 
  mixture 
  to 
  give 
  plasticity 
  and 
  cohesion 
  to 
  the 
  

   bricks, 
  which 
  would 
  be 
  entirely 
  lacking 
  without 
  it. 
  When 
  clay 
  

   and 
  hard 
  limestones 
  are 
  the 
  raw 
  materials 
  two 
  different 
  methods 
  

   have 
  been 
  used. 
  In 
  the 
  first 
  the 
  limestone 
  is 
  calcined 
  and 
  slaked. 
  

   A 
  mixture 
  is 
  then 
  made 
  of 
  clay 
  with 
  the 
  slaked 
  lime. 
  In 
  the 
  

   other 
  method 
  the 
  clay 
  is 
  first 
  dried 
  and 
  ground 
  and 
  then 
  mixed 
  

   dry 
  with 
  pulverized 
  limestone. 
  In 
  both 
  methods 
  the 
  resulting 
  

   mixtures 
  are 
  then 
  made 
  into 
  bricks 
  and 
  dried 
  for 
  burning. 
  

  

  In 
  preparing 
  the 
  wet 
  marls 
  and 
  clays 
  of 
  New 
  York 
  for 
  burning 
  

   in 
  shaft 
  kilns 
  the 
  approved 
  practice 
  is 
  to 
  first 
  dry 
  and 
  grind 
  the 
  

   clay 
  and 
  to 
  then 
  add 
  it 
  in 
  proper 
  proportion 
  to 
  the 
  wet 
  marl. 
  

   The 
  mixture 
  is 
  then 
  perfected 
  in 
  pug 
  or 
  edge 
  runner 
  mills 
  and 
  

   the 
  slurry 
  is 
  balled 
  and 
  dried 
  for 
  calcination. 
  

  

  Various 
  methods 
  of 
  balling 
  slurry 
  are 
  employed. 
  Sometimes 
  

   it 
  is 
  spread 
  on 
  a 
  floor 
  and 
  cut 
  up 
  in 
  blocks. 
  Brick-making 
  ma- 
  

   chines 
  discharging 
  a 
  continuous 
  stream 
  of 
  slurry 
  which 
  can 
  be 
  

   cut 
  to 
  size 
  by 
  wires 
  or 
  knives 
  are 
  employed 
  in 
  both 
  New 
  York 
  

   and 
  Pennsylvania. 
  The 
  German 
  dry 
  brick-press 
  requiring 
  only 
  

   a 
  small 
  quantity 
  of 
  water 
  in 
  the 
  mixture 
  is 
  in 
  use 
  in 
  one 
  plant. 
  

   With 
  marl 
  and 
  clay, 
  or 
  chalk 
  and 
  clay, 
  it 
  is 
  unnecessary 
  to 
  make 
  

   bricks; 
  the 
  material 
  separates 
  into 
  lumps 
  by 
  shrinkage 
  and 
  dry- 
  

   ing 
  and 
  can 
  then 
  be 
  broken 
  easily 
  to 
  suitable 
  size. 
  This 
  is 
  the 
  

   practice 
  abroad 
  with 
  kilns 
  of 
  the 
  Johnson 
  type 
  and 
  in 
  drying 
  

   marls 
  and 
  clays 
  for 
  shaft 
  kilns 
  in 
  New 
  York 
  state. 
  

  

  For 
  the 
  preliminary 
  drying 
  of 
  clay 
  a 
  revolving 
  dryer 
  of 
  some 
  

   form 
  or 
  other 
  is 
  found 
  most 
  satisfactory, 
  while 
  for 
  drying 
  brick 
  

   or 
  balled 
  slurry 
  tunnel 
  dryers 
  are 
  better. 
  Narrow 
  brick 
  tunnels 
  

   are 
  used 
  and 
  the 
  bricks 
  are 
  stacked 
  on 
  shelving 
  fitted 
  to 
  light 
  

   cars 
  which 
  are 
  run 
  into 
  the 
  tunnels. 
  Drying 
  is 
  effected 
  either 
  by 
  

   heat 
  from 
  steam 
  coils 
  set 
  in 
  the 
  bottom 
  of 
  the 
  tunnels 
  or 
  by 
  a 
  

   current 
  of 
  heated 
  air 
  passing 
  through 
  them. 
  This 
  system 
  of 
  

   balling 
  and 
  drying 
  slurry 
  is 
  taken 
  from 
  German 
  practice 
  and 
  i& 
  

  

  